Use the shx package instead of the pipe package (#107)

* Use the shx package instead of the pipe package

The pipe package (gopkg.in/m-lab/pipe.v3) doesn't work as expected
because not only it doesn't support contexts its RunTimeout()
method does not correctly timeout.  As a result, the latency
numbers cannot be trusted.

This commit replaces the pipe package with the shx package in the
ScamperDaemon.trace().	Once we have validated the new code works
as expected, the Scamper.trace() will also use the shx package.

Because there are multiple traces being performed in parallel,
the new code improves log messages by including the context
identifier so individual contexts can be easily identified.

Tested the changes locally using docker-compose.

* Change the exepcted error message in scamper_test.go

* Remove unnecessary variable declaration

* Remove the remaining references to the pipe package

This commit removes the remaining references to the pipe package
and simplifies the code that uses the shx package.

This commit also adds some flags to make it easier to configure
scamper without having to edit code and rebuild traceroute-caller
for different configurations.  Specifically, "-O ptr" can be
enabled/disabled and tracelb's "-W" flag can be specified.

Run "./traceroute-caller -h" and/or see docker-compose.yaml for
an example of running with values different than the defaults.

The changes were tested locally with "go test ./..." and
docker-compose.

* Make changes suggested in code review

Author: Saied Kazemi

caller.go

@@ -41,13 +41,21 @@ import (
 )
 
 var (
+	// TODO: scamper and its commands (e.g., tracelb) support a
+	// relatively large number of flags.  Instead of adding these
+	// flags one by one to traceroute-caller flags, going forward
+	// it's much better to have traceroute-caller read a configuration
+	// file in textproto format that would support all scamper and
+	// its command flags.
 	scamperBin        = flag.String("scamper.bin", "scamper", "The path to the scamper binary.")
 	scattachBin       = flag.String("scamper.sc_attach", "sc_attach", "The path to the sc_attach binary.")
 	scwarts2jsonBin   = flag.String("scamper.sc_warts2json", "sc_warts2json", "The path to the sc_warts2json binary.")
-	scamperCtrlSocket = flag.String("scamper.unixsocket", "/tmp/scamperctrl", "The name of the UNIX-domain socket that the scamper daemon should listen on")
-	scamperTimeout    = flag.Duration("scamper.timeout", 900*time.Second, "how long to wait to complete a scamper trace.")
-	outputPath        = flag.String("outputPath", "/var/spool/scamper", "path of output")
-	waitTime          = flag.Duration("waitTime", 5*time.Second, "how long to wait between subsequent listings of open connections")
+	scamperCtrlSocket = flag.String("scamper.unixsocket", "/tmp/scamperctrl", "The name of the UNIX-domain socket that the scamper daemon should listen on.")
+	scamperTimeout    = flag.Duration("scamper.timeout", 900*time.Second, "How long to wait to complete a scamper trace.")
+	scamperPTR        = flag.Bool("scamper.tracelb-ptr", true, "Look up DNS pointer records for IP addresses.")
+	scamperWaitProbe  = flag.Int("scamper.tracelb-W", 25, "How long to wait between probes in 1/100ths of seconds (min 15, max 200).")
+	outputPath        = flag.String("outputPath", "/var/spool/scamper", "The path of output.")
+	waitTime          = flag.Duration("waitTime", 5*time.Second, "How long to wait between subsequent listings of open connections.")
 	poll              = flag.Bool("poll", true, "Whether the polling method should be used to see new connections.")
 	tracerType        = flagx.Enum{
 		Options: []string{"scamper", "scamper-daemon", "scamper-daemon-with-scamper-backup"},
@@ -77,9 +85,11 @@ func main() {
 	defer promSrv.Shutdown(ctx)
 
 	scamper := &tracer.Scamper{
-		Binary:         *scamperBin,
-		OutputPath:     *outputPath,
-		ScamperTimeout: *scamperTimeout,
+		Binary:           *scamperBin,
+		OutputPath:       *outputPath,
+		ScamperTimeout:   *scamperTimeout,
+		TracelbPTR:       *scamperPTR,
+		TracelbWaitProbe: *scamperWaitProbe,
 	}
 	scamperDaemon := &tracer.ScamperDaemon{
 		Scamper:          scamper,

docker-compose.yaml

@@ -64,3 +64,8 @@ services:
       - -poll=false
       - -tcpinfo.eventsocket=/local/tcpevents.sock
       - -tracetool=scamper-daemon
+      - -scamper.timeout=3600s
+      - -scamper.tracelb-ptr=false
+      - -scamper.tracelb-W=30
+      - -IPCacheTimeout=600s
+      - -IPCacheUpdatePeriod=60s

go.mod

@@ -3,12 +3,10 @@ module github.com/m-lab/traceroute-caller
 go 1.16
 
 require (
-	github.com/araddon/dateparse v0.0.0-20200409225146-d820a6159ab1 // indirect
 	github.com/go-test/deep v1.0.7
 	github.com/gocarina/gocsv v0.0.0-20210408192840-02d7211d929d // indirect
 	github.com/kr/pretty v0.2.0
-	github.com/kr/text v0.2.0 // indirect
-	github.com/m-lab/go v1.4.0
+	github.com/m-lab/go v0.1.45
 	github.com/m-lab/tcp-info v1.5.3
 	github.com/m-lab/uuid v0.0.0-20191115203855-549727171666
 	github.com/prometheus/client_golang v1.10.0